Pre-harvest factors

Pre-harvest factors

1. temperature

   • sunburn
   • can acclimatise fruit to warm post harvest temps

2. light

3. soil quality

4. irrigation

   • MC% at harvest affects pinking of lettuce
   • wet crop deteriorates quicker

5. fert

   • high N
     • internal browning (tomato)
     • hollow stem/ hollow heart (broccoli/cauli)
     • broccoli
       • more = larger head and higher MC%
         • but reduces shelf life
     • high N:K
       • causes greying in potatoes
         • chlorogenic and citric acid
           • whichever is greater in quantity gets the iron
             • chlorogenic + iron = grey
     • lengths shelf life in a dry crop, shortens in a wet one
   • calcium, copper and manganese all have deficiency effects
   • calcium spray
     • reduces waste in apple storage
       • Sharpless and Johnson, 1977

6. maturity

   • immature fruit is more robust

7. harvesting

8. time to consumer

9. Onions and water

   • maintain yield with reduced irrigation in later growth
   • more sensitive to deficit in early development
   • Low OM and late deficit reduces sprouting at 3months of store
     • no significant effect after 6months

10. variety

    • broccoli shelf life
      • packman almost twice as long as majestic
    • some onions store longer than other
      • shorter storing varieties may yield better

11. weather

    • cracking
    • increased disease
    • wind
    • hail